What's under the floor?

berth control

berth control

New Member
Nov 16, 2008
886
Saugatuck, MI
Boat Info
1985 270 Sundancer
Engines
3.7 liter Mercruisers
I was working on my boat and noticed that there is a big area under the couch, kitchenette, floor, and mid berth that I can't get to. I was wondering what is under those areas - I assume it's foam.

If so, will it keep my boat from sinking to the bottom if it gets swamped? A guy once told me that any boat that is less than a yacht classification by the CG has to be buoyant even when swamped, is this true?

Your help is appreciated! It will keep me from drilling holes to see:grin:
 
2 types of flotation requirements. Basic and Level.

The Level Flotation Standard applies to monohull outboard powered boats less than 20 feet in length except sailboats, canoes, kayaks, inflatables, submersibles, race boats, surface effect vessels and amphibious vehicles.

BASIC FLOTATION. Builders of inboards and inboard-outdrives are required to comply with the Basic Flotation portion of the Coast Guard Flotation Standard. Basic Flotation requires a fully loaded boat to float with some portion of the boat above the surface of the water when it is swamped. This means that the boat must contain sufficient flotation to support two-fifteenths (2/15) of the persons capacity and 25 percent of the dead weight. Basic Flotation is designed to give the survivors of a boating accident in which the boat has swamped something on the hull to hang onto. The advantages of Level Flotation versus Basic Flotation
are obvious.

This is a pretty good example of "Basic flotation"

sunken-sealine-37-powerboat.jpg



LEVEL FLOTATION. Level Flotation will increase both your ability to survive and the ability of rescue groups to locate you after and accident has occurred. Level Flotation does just what its name sounds like. If a boat fills with water, Level Flotation will make the boat float level. You and your passengers will actually be able to remain inside the boat even though it is full of water. There you will be warmer, feel safer, be less in danger of drowning and will provide a larger target for rescue groups to locate. If the seas are calm, you might be able to bail the water out of your boat and if the powerhead of your motor wasn’t damaged by immersion in the water, you might be able to return to shore under your own power.

GOLD%20STAR%20BOATS%20floatation_11_img_0.jpg


http://files.dnr.state.mn.us/education_safety/safety/boatwater/backyardboatbuilders.pdf
 
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Thanks for the response Vince, I really appreciate you looking up the link and the picture. Those areas I mentioned must be foam then, and I won't mess with them. There are some big areas in the bilge that I assume are foam too, where the batteries, water, and water heater sit.

This makes me wonder about re-powers with bigger motors than the boat came with. Should it be a concern that the added weight would compromise the basic flotation?
 
The Coast Guard info you provided shows no requirements for floatation if the boat is 20 feet or more in length. His is 27 feet. I believe my boat has no floatation added. I can see more than 90% by looking into lockers and have seen 32s being built. No foam that I noticed in the build process.
 
There is most likely not any foam installed there, its 99% just dead space or some part of a system is located there.
 
Just find some pics of boats being built. You'll see how much of that space is empty as was just said.
 
sbw1 said:
The Coast Guard info you provided shows no requirements for floatation if the boat is 20 feet or more in length. His is 27 feet. I believe my boat has no floatation added. I can see more than 90% by looking into lockers and have seen 32s being built. No foam that I noticed in the build process.
Click to expand...

The wording of the regs is somewhat confusing, but the way interpret it, monohull boats over 20ft must meet basic flotation requirements, while monohull boats under 20ft must meet level flotation requirments.

My guess is that Tiara is meeting the requirements in a not so obvious way.. Is your hull cored?

Go here and type in flotation in the problem field and see all the boats that got recalled.
http://www.uscgboating.org/recalls/recalls_database.htm


This provides a nice summary of the rules.
http://www.uscgboating.org/safety/boatbuilder/flotation/intro.htm
 
I can't imagine sea ray making such large areas like under the couch and mid berth just dead space - but if it is, I will open them up for storage. I just don't want to cut in and damage what may be a water tight chamber or something.

The way I was told by the previous owner of my boat is that when you look at the yellow aluminum CG tag in the boat that gives capacities, if it does not say "yacht", then it has to be able to float. Maybe he was wrong.

I went to the link and entered "flotation", seems like a lot of smaller boats, not bigger ones.
 
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Vince_nj1 said:
The wording of the regs is somewhat confusing, but the way interpret it, monohull boats over 20ft must meet basic flotation requirements, while monohull boats under 20ft must meet level flotation requirments. [/URL]
Click to expand...

Look at the chart on page 16 in your original CG Saftey.......... Less than 20 feet, floatation; equal to or greater than 20 feet, no floatation. Am I missing something?

Yes, my hull is cored above the water line. That must add some floatation, but 19,000 pounds of positive lift? I suppose it's possible but don't know how to do the math.
 
berth control said:
I can't imagine sea ray making such large areas like under the couch and mid berth just dead space - but if it is, I will open them up for storage. I just don't want to cut in and damage what may be a water tight chamber or something.
Click to expand...

My 37 SR express had a nice little locker aft of the TV locker at the same level of the sofa. There was even an inspection panel to lift. I was surprised by how little space was in there due to the dead rise of the hull in that location. There was also a yellow warning sticker that said "Not for Storage." I'm sure the worry is someone would place something heavy and sharp in there that would rattle around and end up wearing a hole in the hull. The space under the sofa was probably equally bad for storage and probably had structural stuff related to the base of the sofa that slid out to make another bed.

The Tiara has storage areas under the sofa, but its use is somewhat limited because the area acts as a return air vent for the A/C. I used to store blankets there until I saw how fuzzed up my A/C filter got from air movement over wool blankets. I now use it for seldom used charts and tools.
 
Ok..Its clear that can not determine by reading the regs if your boat will float when flooded with water. Therefore we will need to perform a test... Please remove all hoses connected to the seacocks and flood your boat with water. Wait exactly 18 hours from the time that it stops taking on water, take a few pictures and then post them here. We can continue the discussion tomorrow. :thumbsup:
 
Right now it would sit pretty on the ice. :smt100 And I don't have any seacocks or through hulls. :grin:
 
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I know people that have had a boat disappear from underneath them in less than 2 minutes after hitting something (28 foot)... I would not count on your boat floating if it fills up with water... in fact... I would count on it going to the bottom.
 
so i should not damage any flotation devices by looking in the areas with a holesaw? If it's foam I can just leave it alone - if not I gained a bunch of storage?
 
Four Suns said:
I know people that have had a boat disappear from underneath them in less than 2 minutes after hitting something (28 foot)... I would not count on your boat floating if it fills up with water... in fact... I would count on it going to the bottom.
Click to expand...


Must of had diesels.. A gas boat would float with all the CO trapped in the cabin..:lol:
 
I am just a little nervous about taking a holesaw to a bunch of areas in my boat that are possibly meant to keep it afloat. Nobody else has big areas like this in their boat that are dead space? Do you guys have storage under your mid berth? What about under the seats of most dinettes? Kitchenette cabinets that sit a foot off the floor, what's under there? I know some areas are not that big because the hull is curved in there, but there is still a lot of space.
 
I gutted an 89 wellcraft aft cabin last year to include the areas beneath the batteries, v berth, below the cabinets and such and found no foam. It wasn't a sea ray but same era and regs to follow. I'd like to know too but don't want my boat to be the the test. :)
 
IMHO - Just because there is no foam, I would be real careful with a hole saw. You never know what wires/lines may be running behind that glass.(Grin)
 
berth control... I would think that if there was usable space, searay would have used it. I do not reccomend drilling observation holes in your boat, as there must be somebody out there who KNOWS whats in those areas. js
 
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